Recent salmonella outbreaks that sickened at least 523 people and sent dozens to the hospital underscore “serious weaknesses” in the U.S. Department of Agriculture’s oversight of poultry plants, according to a study released Thursday by the Pew Charitable Trusts, which also criticized the government’s failure to push more aggressively for recalls of contaminated meat.

A separate investigation by Consumer Reports, also published Thursday, suggested that those lapses have contributed to the prevalence of potentially harmful bacteria that lurk in store-bought chicken. The magazine independently tested more than 300 raw chicken breasts purchased from stores across the country and found that every major brand contained “worrisome amounts” of pathogens such as salmonella and E.coli, including some strains resistant to treatment with antibiotics.